windows batch files: setting variable in for loop

Question

I have a number of files with the same naming scheme. As a sample, four files are called \"num_001_001.txt\", \"num_002_001.txt\", \"num_002_002.txt\", \"num_002_003.txt\"

Answer 1

Your problem is that the variable get replaced when the batch processor reads the for command, before it is executed.

Try this:

SET temp=Hello, world!
CALL yourbatchfile.bat

And you'll see Hello printed 5 times.

The solution is delayed expansion; you need to first enable it, and then use !temp! instead of %temp%:

@echo off
SETLOCAL ENABLEDELAYEDEXPANSION
FOR /R %%X IN (*.txt) DO (
  set temp=%%~nX
  echo directory !temp:~0,7!
)

See here for more details.